I use my vertool force drive an awful lot and on the last car I was machining this week I could barely hold the polisher as it was pulling and I think it needs the bearings greased perhaps- I have it 6months and never serviced it

Has anyone a good tutorial or video link they could share to service the machines?

I'm glad he does not service mine.
Bevel gears require specific lubrication and I doubt Flex would have chosen something unsuitable and what is in there is not contaminated there is no reason to change or recommend a change.
It will generally be a softer grease, as shown in the Flex, that is used because the gears require constant lubrication and are actually better run in oil rather than grease but leakage issues can be a problem, so a runny grease is used that flings and fills the gear teeth with lubricant but does not leak from the case.
All my Flex tools are years old, work as on day one, and have not required any servicing for grease starved, worn bearings etc. That is not to say the Vertool might not have issues.
I'm not sure what you mean by pulling but it does not sound like a gear related problem
If it is faulty and only six months old I would send it back, let them check and if necessary replace it rather than take it apart yourself.
That is a standard wheel bearing grease he is using in the video and its operation is different to that of a polisher with that internal mechanism.

Pulling sounds more like a pad /polish /paint combination interface issue. Noisy or vibrating / rattling /speed variation might indicate machine needs servicing.
Have you tried it on another car?
Only other thing does it have a counter weight that has become dislodged /moved?

Pulling sounds more like a pad /polish /paint combination interface issue. Noisy or vibrating / rattling /speed variation might indicate machine needs servicing.
Have you tried it on another car?
Only other thing does it have a counter weight that has become dislodged /moved?

Same pad and polish combo I use on most cars, To me it feels off balance so what you are suggesting sounds possible. Wonder is there somewhere I could send it to be looked at properly